Auxiliary operating attachment for drills.



A. G. MCCORMACK.

AUXILIARY OPERATING ATTACHMENT FOR DRILLS.

APPLICATION FILED AUG.3. 1914.

1,138,767, Patented May1'1,1915.

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Atty S THE NORRIS PETERS CO4, FHOTO-LITHOu WASHINGTON. D, C.

ANGUS GILBERT MCCORMAGK, OF PORT ARTHUR, ONTARIO, CANADA.

AUXILIARY OPERATING ATTACHMENT FOR DRILLS.

Specification of Letters Patent.

Patented May '11, 1915.

Application filed August 3, 1914. Serial No. 854,795.

To all whom, it may concern Be it known that I, ANGUS GILBERT Mo- OORMACK, of the town of Port Arthur, in the District of Thunder Bay, in the Province of Ontario, Canada, have invented certain new and useful Improvements in Auxiliary Operating Attachments for Drills, of which the following is the specification.

My invention relates to improvements in auxiliary operating attachments for drills and the object of the invention is to devise means for exerting increased leverage against the drill chuck of a breast drill when the drill is being operated by hand in the usual manner and it consists essentially of a lever provided with a recess in its underside located intermediately of its length and an orifice extending from the base of the recess to the top of the lever, an orifice extending vertically through the end of the short arm of the lever, a screw spindle extending freely through such orifice, and means for swingably supporting the lower end of the spindle so as to bear against a suitable support as hereinafter more particularly explained by the following specification.

Figure 1, is a perspective View of my device showing the upper portion of the drill broken away. Fig. 2, is an enlarged sectional view through the major portion of Fig. 1 showing the drill complete.

In the drawings like letters of reference indicate corresponding parts in each figure.

A is a lever arm provided with a recess A extending upwardly from its under face. The lever A is preferably provided with a boss A by which the thickness of the lever is increased around the recess.

A is an orifice extending upwardly from the base of the recess through the top of the lever.

A is a cup held within the bottom of the recess and forming a ball race for ball bearings A.

A is an orifice extending vertically through the end of the lever.

B is an inverted U-shape strap secured on a suitable support such as the bench B by bolts B B is an orifice formed in the strap.

G is a bearing screw held freely within the orifice A of the lever and passing freely through the orifice B of the strap.

C is a nut threaded on tothe screw beneath the strap B so as to bear upwardly against the horizontal portion of the strap.

D is a breast drill of any usual type provided with a suitable chuck D in which the bit D and an operating handle D is secured. The balls of the ball bearings A take up the upward thrust of the chuck D. The outer end of the lever arm A is formed into a suitable handle A".

In operating the device the operator grips .the handle A bearing downwardly thereon and at the same time turning the brace D with the other hand. By this means great pressure is exerted on top of the chuck so as to force the bit into the work.

By adjusting the screw C, the bit D may be raised or lowered to bore any article from one-sixteenth of an inch to an article as thick as the bit is long. This adjustment permits the lever to be level when the boring operation begins which insures greater accuracy of boring.

When the work is between the bit and the bench, the end of the lever arm A, through which the bearing screw extends, is carried against the head of the screw which forms the fulcrum. When the lever arm is depressed sufiiciently during the process of boring to bind on the screw, the boring of the bit ceases. The screw is then turned by hand so as to carry the head to a lower position to form a new point of fulcrum for the lever arm.

It has been found by actual practice that sufficient pressure can be obtained to drive the bit quickly through any material desired.

In Fig. 1 I have shown the nut on the spindle C provided with hooks C to which chains may be secured to connect the device to a suitable fulcrum support.

What I claim as my invention is- 1. An operating attachment for breast drills comprising a lever provided with an orifice at one end and a recess into which the brace chuck fits and an orifice extending from the recess through which the shank of the drill extends and a vertical spindle suitably threaded and extending through such orifice, a nut carried on the spindle and a strap for connecting the nut to a suitable base, as and for the purpose specified. v

2. An attachment for breast drills comprising a lever provided With a recess in dle extends and against the horizontal por- Which the drill chuck fits and an orifice ,tionof which the nut bears, as and for the at one end, a vertical spindle suitably purpose specified.

threaded through such orifice, a nut carried ANGUS GILBERT MOCORMACK. on the spindle and an inverted U-shape Witnesses:-

strap secured to a suitable base and having E. PENNOCK,

an orifice through which the threaded spin- M. EGAN.

Copies ,of this ,patent may'iibe obtained .forrfive cents: each, by; addressing the G'ommissionerof latents, Washington, D. 0. 

